Long-Term Debt - Schedule of Interest Expense Related to Notes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Debt Instrument [Line Items]
Total interest expense related to the Notes			$ 2,900	$ 3,200
3.00% Convertible Senior Notes Due 2025
Debt Instrument [Line Items]
Contractual interest expense	$ 1,308	$ 1,308	3,924	3,924
Amortization of debt discount	943	886	2,786	2,617
Amortization of issuance costs	237	223	700	658
Total interest expense related to the Notes	$ 2,488	$ 2,417	$ 7,410	$ 7,199